1. Baweja, B.K., Raju, 1984. Ground-water potential of hard rock areas in the Noyil, Amaravati and Ponnani Basins, South India. Groundwater in hard rocks. Project 8.6. International Hydrological Programme, Unesco, Paris
2. Hydraulics of Groundwater;Bear,1979
3. Botha, F.S., 2000. Groundwater resource development in hard crystalline rock aquifers in the Nebo Plateau, South Africa. Unpublished MSc thesis, University of Pretoria, Pretoria
4. Waterbestuur: Multi-disiplinere benadering op die Nebo Graniet Suite, Noordelike Provinsie;Botha,1997
5. Dijon, R., 1984. Ground-water exploration in precambrian rocks of Northern Cameroon. Ground Water in Hard Rocks, United Nations, p. 171